A state-of-the-art hybrid tandem mass spectrometer (MS/MS) equipped with High Performance Liquid Chromatography (HPLC) and autosampler for quantitative assays of biological samples is requested. The instrument is chosen to support the thematic research of UCLA investigators using proteomics and metabolomics to study human health and disease. This instrument will be a vital component to support the specific aims of a broad range of NIH-funded projects. The projects involve the measurement of a variety of molecular species, including peptides digested from proteins associated with immune cells, intestinal lavage samples, core metabolic pathways such as glycolysis, lipids associated with biosynthetic pathways, inflammation response, and dysfunctional HDL. The proposed mass spectrometer system will be supported and administered by the UCLA Molecular Instrumentation Center (MIC), a campus-wide, integrated facility formed to enhance the accessibility of existing shared, sophisticated instrumentation facilities to the broader research community at the institution. Although triple quadrupole mass spectrometers excel over most other mass spectrometry designs in their ability to perform high throughput quantitative analysis of complex mixtures over a large dynamic range, we are requesting a newly developed hybrid high resolution quadrupole Orbitrap, the Q-Exactive. The Q-Exactive offers choices of scan functions amenable to quantitation not available to traditional triple quadrupole instruments, and offers versatility and flexibility in method development crucial to a core facility. In discovery applications, the Orbitrap analyzer, with its high mass accuracy and high resolution, can reduce the candidate identifications by five-fold or more. The dynamic range, greater than 4 orders of magnitude, and sensitivity are comparable to that achieved on current triple quad instrumentation.